1. Bring 2 1/2 cups water, rice, and a pinch of salt to a boil in a saucepan. Reduce heat, cover, and simmer until grains are tender and water has been absorbed, 40 to 50 minutes. Remove from heat; let stand 10 minutes, then fluff with a fork.

2. Heat oil in a nonstick pan over high heat. Pat fish dry. Cook fish until golden brown on outside but still rare in center, 1 1/2 to 2 minutes a side. Let cool slightly.

3. Meanwhile, using tongs, toast nori sheets, one at a time, over the flame of a gas burner until they begin to shrivel and become fragrant.

4. Mix together lemon juice, soy sauce, and chile sauce in a bowl. Divide rice among 4 plates and drizzle with half of sauce. Arrange avocado and cucumber on top of rice. Break salmon into chunks and divide among plates. Drizzle with remaining sauce, and top with cilantro and chile. Break nori into pieces and serve on the side.